Doxycycline Side Effects in Dogs

Doxycycline is a very strong and effective member of the
tetracycline family of antibiotics. While currently not approved for
use in animals, many veterinarians prescribe it for certain conditions
such as Lyme disease and Ehrlichiosis. It is also used for conditions
where the organs have a special barrier in place that prevent other
antibiotics from crossing these barriers in order to kill intracellular
parasites and infections. Doxycycline doesn’t kill the bacteria, it
actually prevents it from reproducing, allowing the dog’s immune system
to kill off the bacteria. Doxycycline is also known for having an
extended effectiveness, making it highly beneficial in treating
particularly difficult conditions.

Doxycycline Side Effects

Nausea and vomiting are the most common side effects associated
with doxycycline. This side effect can typically be overcome by
providing food along with the medication. While most tetracycline-type
medications are not given with food because food prevents the
antibiotic from being absorbed, this does not seem to be a problem with
doxycycline.

Loss of appetite is a secondary side effect that goes hand in hand with the nausea and vomiting.

Diarrhea is an uncommon side effect of doxycycline. It is
frequently an indicator that the dosage is too high and your dog should
be taken to the veterinarian to have his dosage adjusted or to
determine the cause of the diarrhea.

Doxycycline has a pH level that can cause irritation and eventual
scarring in the esophagus should the pill get caught in the throat. To
avoid this side effect, ask to use the liquid form of doxycycline.

Doxycycline can also cause staining or yellowing of the teeth in
young animals. Doxycycline binds to calcium, and calcium is the key
component in forming teeth.

There are some very rare side effects with doxycycline. Changes in
blood cells, liver damage and sensitivity to sunlight are extremely
rare, but can occur.

Drug Interactions and Precautions

Doxycycline can be rendered ineffective when used in combination
with other drugs. Medications containing calcium, such as antacids,
should be avoided for this reason. The calcium binds to the doxycycline
making it ineffective. Dietary supplements containing iron should be
given several hours after doxycycline is given because iron can also
prevent doxycycline from being effective.

If your dog is on digoxin (a heart medication) doxycycline should not be used as it can increase the strength of the digoxin.

If your dog’s immune system is in a compromised state, conditions
such as kidney disease, diabetes or other conditions that make it
difficult for your dog to fight infection, doxycycline should not be
used. Another antibiotic should be used in order to keep your dog’s
immune system as strong as possible.

Whether your dog is being treated for Lyme disease or a severe
kidney or urinary tract infection, if doxycycline is prescribed, it is
important to keep an eye on your dog’s progress and how he reacts to
this medication. Vomiting and diarrhea can cause dehydration,
suppressing his immune system and preventing his body from fighting the
infection. It is also important that your veterinarian know what
dietary supplements or other over the counter medications you are
giving your dog so he can be sure to avoid any negative interactions.
Doxycycline can certainly help restore your dog’s health, it should
just be used with care.